Our research efforts have been aimed at defining the physiochemical properties and primary structure of human monoclonal immunoglobulins. The overall purpose of these studies is to help understand the (1) genetic basis of antibody formation, (2) the nature and origins of the deletions found in heavy chain disease proteins and (3) the localization of the antibody-combining site and the basis of antibody specificity. We are presently defining the amino acid sequence of three monoclonal immunoglobulins: IgG GAR, IgG Sm and Bence-Jones protein White. IgG GAR is a gamma 2 myeloma protein which binds riboflavin and contains lambda-type L chains. We are completing the amino acid sequence of the V regions of the H and L chains. Protein IgG Sm is a myeloma protein with apparent deletions in both H and L chains. We are attempting to define the nature of the deletion in the H-chain. Protein White is a lambda-type Bence-Jones protein which contains carbohydrate. We have almost completed the sequence of the V-region and the point of carbohydrate attachment.